Question

Caspases are apoptosis-inducing proteins activated by tumor suppressor proteins such as p53

Select one:

a. True

b. False

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entrioles are only found in a cell during the M phase of the cell cycle

Select one:

a. True

b. False

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Cyclin-dependent kinases (CDKs) can be activated or deactivated via phosphorylation and dephosphorylation

Select one:

a. False

b. True

Answer 1

The statement given is true .

Because caspases are the proteolytic enzymes the main purpose of caspases is to induce cell death by apoptosis by intrensic and extrensic pathways. Where generally cells which are damaged,mutated or after there life span leads to cell death by releasing certain substances like cyt c into cytoplasm so that the P53 protein of Tp53 gene recognises and activates caspase after several series of process caspase 3 generally cleaves the cell and execute death program.Here caspase 3 is an effector caspase.

True statement.

Centrioles are found only during cell division because these are present near the nucleus only where they are attached to the centrosomes for the formation of microtubules.where these are packed mainly by pericentriolar material and centrosome are divided when cell division occures so that they are used to build mitotic spindle fibres.

True statement .

Where CDK's are mainly activated by the phosphorylation by kinase that is cdk activating kinase (CAK). Where it pairs with the cyclins for regulating the cell cycle. Where dephosphorylation by phosphatases results no binding of cyclins and CDK's .So cell cycle regulation is stopped.