DNA and diversity

Question 1

What is the male gamete in humans?

Answer 1

Sperm

Question 2

What is a zygote?

Answer 2

A fertilised egg

Question 3

How are gametes formed?

Answer 3

By Meiosis

Question 4

Are gametes haploid or diploid?

Answer 4

Haploid

Question 5

After replication, what are the 2 copies of each chromosome called?

Answer 5

Chromatids

Question 6

When the DNA condenses what is formed?

Answer 6

2 double armed chromosomes made from sister chromatids

Question 7

When does crossing over occur in meiosis?

Answer 7

In meiosis 1

Question 8

What are the 2 main events in meiosis that lead to genetic variation?

Answer 8

Crossing over and independent segregation or assortment of chromosomes

Question 9

What is independent assortment or segregation?

Answer 9

In meiosis when chromosomes from Mum and Dad produce gametes with a random assortment or combination of those chromosomes.

Question 10

How many cells are produced of what type after meiosis?

Answer 10

4 haploid cells

Question 11

The more variety we find in a population…..

Answer 11

….the more genetically diverse it is

Question 12

Does the DNA within a species vary much?

Answer 12

No, all have the same genes, but different alleles

Question 13

The more alleles there are in a population…..

Answer 13

…..the more genetically diverse it is

Question 14

What is a genetic bottleneck caused by?

Answer 14

an event which causes a big drop in numbers in the population. This reduces the number of alleles (think Seals)

Question 15

What is the Founder effect?

Answer 15

A type of genetic bottleneck, when a few organisms start a new colony. (Think Amish)

Question 16

What can cause a Founder effect?

Answer 16

Migration leading to geographical isolation. (Could be a result of religion too in humans)

Question 17

Selective breeding of plants can reduce genetic diversity. True or False?

Answer 17

True

Question 18

Give 2 arguments for selective breeding

Answer 18

High yielding plants and animals
Increased resistance to pests and diseases
Increased tolerance of conditions (eg hot or cold)

Question 19

Give 2 arguments against selective breeding

Answer 19

Health problems (think doggies who can't breathe!)
Increased susceptibility to disease