DNA T1 '25

Question 1

What shape is DNA?

Answer 1

double helix

Question 2

Who successfully discovered the structure of DNA and when?

Answer 2

James Watson and Francis Crick in 1953.

Question 3

What is in a nucleotide?

Answer 3

nitrogenous base, a phosphate and a sugar. (sugar is always represented as a pentagon)

Question 4

What are the names of the 4 nitrogenous bases and what do they pair with?

Answer 4

A- adenine (pairs with thymine)
T- thymine (pairs with adenine)
C- cytosine (pairs with guanine)
G- guanine (pairs with cytosine)

Question 5

What is the name of sugar in DNA?

Answer 5

Deoxyribose

Question 6

what are a females chromosomes?

Answer 6

XX

Question 7

What is DNA’s full name?

Answer 7

Deoxyribonucleic acid

Question 8

what are male chromosomes?

Answer 8

XY

Question 9

Name the complimentary pairs:
TCGATCGA

Answer 9

AGCTAGCT

Question 10

What is haploid?

Answer 10

organism that has a single set of chromosomes such as gametes. (n) occurs in meiosis

Question 11

what is diploid?

Answer 11

organism that has 2 sets of chromosomes, so every other cell parts from gametes in the body (somatic cells). occurs in mitosis. represented as 2n.

Question 12

What is meiosis?

Answer 12

when cells divide twice into 4 (daughter) cells. occurs in gametic cells and there is gene variation, meaning DNA crosses over. it is a reduction division used to make gametes. haploid (n).

Question 13

what is mitosis?

Answer 13

mitosis occurs in somatic cells and us used for growth and prepare. there is 1 division, making 2 (daughter) cells. it is diploid (2n.)

Question 14

What 6 things to remember and list about differences in mitosis and meiosis?

Answer 14

cell type
no. of daughter cells
variation
purpose
haploid or diploid

Question 15

What is homozygous recessive?

Answer 15

tt

Question 16

what is homozygous dominant?

Answer 16

TT

Question 17

what is heterozygous?

Answer 17

Tt

Question 18

what is PMAT?

Answer 18

Prophase
Metaphase
Anaphase
Telophase

Question 19

what happens in prophase?

Answer 19

chromosomes condense and crossing over occurs (in meiosis)

Question 20

what happens in metaphase?

Answer 20

pairs of homologous chromosomes line up on cell equator

Question 21

what happens in anaphase?

Answer 21

chromosomes are ripped apart and move to opposite poles of the cell

Question 22

What happens in telophase?

Answer 22

chromosomes are divided into 2 daughter cells.

Question 23

what does homologous mean?

Answer 23

a homologous pair of chromosomes are 2 chromosomes that are the same or the most similar.

Question 24

what is a karyotype?

Answer 24

when chromosome pairs are arranged from tallest to shortest and given a number.

Question 25

how many chromosomes does a human have?

Answer 25

46, 23 pairs. 23 from mum and 23 from dad.

Question 26

What is a phenotype?

Answer 26

a physical expression of a gene (blue eyes, brown eyes, red hair)

Question 27

What is a genotype?

Answer 27

an allele. (BB, Bb, bb)

Question 28

What is the difference between a phenotype and a genotype?

Answer 28

a genotype is what a trait actually is (red hair, tongue rolling) and a phenotype is the expression of that through letters (TT, Tt, tt)

Question 29

what is an allele?

Answer 29

alternate forms of a gene. (TT, Tt, tt)

Question 30

what is a histone?

Answer 30

protein. DNA winds around it

Question 31

What are 2 examples of genetic technology?

Answer 31

Golden rice and insulin being made

Question 32

Golden rice

Answer 32

genetically modified rice that is the exact same as normal white rice, but has more beta-carotene in it. it was made to combat vitamin a deficiencies in 3rd world countries.

Question 33

insulin

Answer 33

insulin can be genetically made when you take out a piece of a plasmid and replace it with a human insulin gene, creating a recombinant DNA. add transgenic bacteria and the recombinant now has the ability to secrete human insulin.

Question 34

What happens in the DNA replication process?

Answer 34

a helicase unzips DNA, and topoisomerase prevents it from supercoiling. you're left with a leading and lagging stand, and ligase joins the Okazaki fragments in the lagging strand. primase adds a primer for DNA polymerase, which then adds the complimentary nucleotides. exonuclease then remove primers.

Question 35

helicase

Answer 35

unzips DNA

Question 36

ligase

Answer 36

joins Okazaki fragments in lagging strand

Question 37

topoisomerase

Answer 37

prevents DNA from supercoiling

Question 38

DNA polymerase

Answer 38

adds complimentary nucleotides

Question 39

primase

Answer 39

adds primers for DNA polymerase

Question 40

exonuclease

Answer 40

removes primers