Biological Classification — BIOLOGY STD 11 Science — Question

Answer the following questions with reference to the anatomy of dicot stem

1. Type of cells present in the hypodermis.
2. Why is the endodermis layer referred to as starch sheath?
3. Why are the vascular bundles present here referred to as 'open' and 'conjoint'?

What is plasma? Write the functions of plasma.

Describe structure of human kidney.

Abhay, a police officer, discovered a human pelvis from the jungle. After checking the reports of missing people, he found that a couple had been missing from that area since a month. Abhay was confused as to whom the pelvis belonged to and therefore, took it to the forensic investigator. The forensic expert reported it to be a female pelvis. Afterwards, the DNA from the missing female's mother and pelvis was matched. Since, both the DNA matched. It confirmed that out of the couple, the lady had died.

1. How did the investigator opened it to be a female pelvis?
2. What other bones of human can be used for sex identification?
3. Give a possible reason for the change in female pelvis.
4. What values are shown by Abhay?

What are the main differences among Chlorophyceae, Phaeophyceae and Rhodophyceae?

Different types of phyllotaxy are shown in the given figures. Name the phyllotaxy shown in (a), (b) and (c). Give one example of each type.

Which important pulses belong to family Fabaceae? Give also their scientific names.

Where are calcium ions stored in a muscle fibre? How do calcium ions affect the process of muscle contraction?

OR

Bring out the role of calcium ions and ATP in muscle contraction.

Ankit, a Xl class student was continuously listening to his sister and her friend's discussion about the growth of plant. They were discussing that plant growth involves three phenomena, i.e., differentiation, dedifferentiation and redifferention. Listening this Ankit interrupted them in between and asked her sister to elaborate the things in detail and the basic phenomenon behind it. As the topic was the part of the Ankit's syllabus also. Her sister explained him that the cells in plant undergo differentiation to attain a maturity in order to perform specific functions.

1. What is dedifferentiation? Name two tissues formed by this process phenomenon.
2. What is redifferentiation?
3. What value is learnt from the Ankit's character as an ideal biology student.

Do you consider a person in coma-living or dead?