BIOLOGY M.C.Q (1 Marks)

1. Pleistocene

2. Pliocene

Explanation:

Pliocene is the epoch of tertiary period of coenozoic era. Man was originated in this era.

2. Wings of birds (sparrow) and pectoral fins of fish.

4. Increasing brain capacity.

2. When a branch ends.

1. Ramapithecus

3. Australia

Explanation:

Prototherians the most primitive mammals which provide an evidence of organic evolution from geographical distribution are found is Australia.

3. Precambrian

Explanation:

The geological time scale of life on earth is divided into four major units: Eons, Eras, Periods, and Epochs. The first three Eons are collectively called Precambrian. It is the stretch of time that involves the formation of the earth and the appearance of life on earth.

Precambrian is divided into Hadean eon (formation of the earth), Archaean eon (appearance of prokaryotes), Proterozoic eon (stable continents with eukaryotes). The final eon is Phanerozoic, which means revealed or visible life and constitutes the age of multicellular organisms.

1. Biogeographical evolution.

2. Cyanobacteria

Explanation:

Cyanobacteria also known as Cyanophyta, is a phylum of bacteria and they obtain their energy through photosynthesis. By producing gaseous oxygen as a byproduct of photosynthesis, Cyanobacteria are thought to have converted the early reducing atmosphere into an oxidising one, which dramatically changed the composition of life forms on Earth, by stimulating biodiversity.

Most scientists believe that for half of Earth's 4.6 billion year history, the atmosphere contained no oxygen, perhaps as long ago as 3.5 billion years.Free oxygen is toxic to anaerobic organisms and rising concentrations may have wiped out most of the Earth's anaerobic inhabitants at that time.

Cyanobacteria were therefore responsible for one of the most significant extinction events in Earth's history. Eventually, aerobic organisms began to evolve, consuming oxygen and bringing about an equilibrium in its availability.

1. Adaptive radiation

Explanation:

Process of evolution of different species in a given area starting from a point and radiating to other area of geography (habitats) is called adaptive radiations. Example : Darwinian finches and Australian marsupials.

2. Cretaceous

Explanation:

Cretaceous period was the last and the longest segment of the mesozoic era. It lasted approx. 79 million years ago. During this time, reptiles were large in number and were dominant.

3. Number of offspring produced.

3. Cretaceous period of mesozoic era.

Explanation:

Cretaceous period of the mesozoic era was the last phase. It was considered as the longest phase of the mesozoic era. It was also known as the age of reptiles.

In this era, the mammals arose from the reptiles. The transition from reptile to mammal were the evolution of warm-bloodedness, of molar occlusion, of the three-ossicle middle ear, of hair, and of mammary glands. 

5. The principle of Hardy-Weinberg equilibrium.

3. Darwin’s finches.

2. Cenozoic

Explanation:

The birds and mammals evolved during the Coenozoic (new life) era. The decline of reptiles allowed diversification of birds and mammals.

1. Hominidae

Explanation:

The Hominidae (also known as great apes) form a taxonomic family of primates, including four genera:

1. Chimpanzees
2. Gorillas
3. Humans
4. Orangutans

3. Java

Explanation:

Java man (Homo erectus erectus or Pithecanthropus erectus), was a sub species of Homo erectus, that lived around 0.6 million years ago. His fossils have been discovered in Java. He lived in caves and used fire.

1. Genetic equilibrium

4. Cro-Magnon man and Neanderthal man.

Explanation:

Cro-Magnon is a name that has been used to describe the first early modern humans (early Homo sapiens). The Neanderthals are an extinct species of human in the genus Homo, possibly a subspecies of Homo sapiens. They are closely related to modern humans, differing in DNA by only 0.3%.

4. Homologous and vestigial organs.

2. Origin

4. Carboniferous

Explanation:

Palaeozoic era is also called as “era of ancient life”. It is divided into six periods, which are namely cambrian (520–505 million years ago), ordovician (505–430 million years ago), silurian (430–410 million years ago), devonian (410–360 million years ago), carboniferous (360–285 million years ago) and permian period (285–250 million years ago). 

Carboniferous period (360–285 million years ago) of palaeozoic era is marked by origin of first reptiles that resembled lizards.

3. Ramapithecus → Homo habilis → Homo erectus → Homo sapiens.

1. Lichens

2. 15

Explanation:

Plate tectonics is the theory that states that Earth's outer shell is divided into several plates that glide over the mantle. The plates act like a hard and rigid shell compared to Earth's mantle. This strong outer layer is called the lithosphere. Plate tectonics is the modern version of continental drift.

The plates consist of two principal types of material, oceanic crust, and continental crust. The earth is considered to have 15 major tectonic plates. Seven of which are primary plates and the rest are secondary plates.

The primary plates are the African plate, the Antarctic plate, the Eurasian plate, the Indo-Australian plate, the North American plate, the Pacific plate, and the South American plate. The secondary plates are the Arabian plate, the Caribbean plate, the Cocos plate, the Juan de Fuca plate, the Indian plate, the Nazca plate, the Philippine Sea plate and the Scotia plate.

3. Both (a) and (b)

2. Contribute to new variation in organism.

Explanation:

Mutations are the raw materials of evolution. Evolution absolutely depends on mutations because this is the only way that new alleles and new regulatory regions can be created.

1. Random and directionless.

Variations during mutations of meiotic recombinations are random and directionless.

3. Cretaceous

Explanation:

Cretaceous period of Mesozoic era occurred on earth about 65-146 million years ago.

During this period, the flowering plants appeared and became dominant, mass extinctions of marine life and some terrestrial life, including dinosaurs occurred and modern continents became well separated.

2. Fusion converting hydrogen of sun to helium.

Explanation:

The sun is a huge sphere of glowing gases that produce energy and light, which make life on Earth possible. The temperature of the sun varies tremendously. At the core of the sun, gravitational attraction produces immense pressure and temperature can reach upto 20 million degrees centigrade.

Hydrogen atoms get compressed and fuse together, creating Helium. This process is called nuclear fusion, and it causes the sun's interior to be extremely hot. Nuclear fusion produces huge amount of energy. The energy radiates outward to the sun's surface, atmosphere and beyond.

The nuclear burning is almost completely shut off beyond the outer edge of the core. At that point the temperature is only half its central value.

4. Adaptive convergence of closely related groups.

3. Hardy-Weinberg law

Explanation:

Hardy-Weinberg law represents the equilibrium of gene frequencies.

According to the Hardy Weinberg law, the allele and genotype frequencies in a population remain constant in the absence of factors responsible for evolution. It states that the sum of all genotype frequencies can be represented as the binomial expansion of the square of the sum of p and q.

This sum is equal to one : ( p + q )² = p² × 2pq × q² = 1.

"p" is the frequency of the dominant allele, and "q" is the frequency of the recessive allele. The "2pq" in the equation shows the frequency of heterozygotes in the population.

1. Huxley

Explanation:

It is generally believed that both mammals and birds are derived from reptiles. Archaeopteryx is a fossil bird showing both reptile and bird features. Hence birds were called glorified reptiles by Huxley.

He was known as "Darwin's Bulldog" for his advocacy of Charles Darwin's theory of evolution.

3. Evolution of different species from a common ancestor.

2. GA

2. Organs with anatomical similarities, but performing different functions.

1. Increasing cranial capacity.

1. Precambrian era

Explanation:

Precambrian is one of the four eras in earth's geological history.

Precambrian actually meant period before the Cambrian period of the Palaeozoic era.

Precambrian is divided into three periods- Azoic (no life), Archaeozoic (invisible life) and Proterozoic (age of early life).

It is believed that life appeared in Archeozoic period of Precambrian era.

1. Azoic era

Explanation:

An eon is the largest timespan in the geological timeline. An eon is subdivided into eras.

The Azoic Era was the oldest and long-lasting stage in the development of earth. There was no evidence of life in this era.

The Azoic era is the era when origin of the continental shelf occurred.

The continental shelf (Pangaea) was formed by the silica rich granite rocks of less density.

4. Allen’s rule.

1. Lobe fish.

4. Greater cranial capacity

Explanation:

Social life and power of speech are not unique characters of man. Several other animals especially, Arthropods lead a social life and power of speech is present in several vertebrates. Superior intelligence does not distinguish man from apes.

Apes are also categorised as intelligent animals. However, apes have a lower cranial capacity (100cc in Gibbon, 400cc in Orangutan and Chimpanzee and 550cc in Gorilla), but man has a higher cranial capacity (1400 - 1450cc). Man also has a higher brain to body weight ratio as compared to apes.

4. Tool maker

Explanation:

The first hominid Homo habilis lived in Africa about 2 million years ago. Homo habilis made primitive stone tools. Thus, they are called tool maker or handy man.

3. Archaeozoic

Explanation:

Archaeozoic era occured before 2.5 billion years ago, when the only life forms were blue-green algae and bacteria.

Evolution of unicellular organisms occurred during this era.

3. Protective resemblance with the surroundings.

1. Von Baer

4. All of the above

Explanation:

The conditions to maintain the Hardy-Weinberg equilibrium are no mutation, no gene flow, large population size, random mating, and no natural selection.

The Hardy-Weinberg equilibrium can be disrupted by deviations from any of its five main underlying conditions.

Hence, Under which condition, Hardy Weinberg's law is violated Natural selection, Mutation and Immigration and genetic drift.

So, the correct answer is 'All of the above'.

1. Pleistocene

Explanation:

Homo erectus was a erect man from middle Pleistocene epoch. It lived from 1.7 to 0.25 million years ago. One of the important species of Homo erectus was the Peking man or Homo erectus pekinensis also called as Homo erectus sinanthropus or Sinanthropus pekinensis.