B16 - chromosomes & genes, cell division, monohybrid inheritance

Question 1

which cell has no nucleus

Answer 1

red blood cells

Question 2

which cells are haploid

Answer 2

gametes

Question 3

which cells are diploid

Answer 3

all body cells except gametes & red blood cells

Question 4

how many chromo. & sets in haploid in humans

Answer 4

n = 23
(n = a set of chromo.)

Question 5

how many chromo. & sets in diploid in humans

Answer 5

2n = 46
-23 pairs
(n = a set of chromo.)

Question 6

note: no. chromo. varies depending on organisms

Question 7

how do you number the human chromo.

Answer 7

-largest pair is 1st
-last pair is 23rd pair (sex chromo.)

Question 8

how long is DNA in each nucleus

Answer 8

2m

Question 9

what is 1 chromo. to DNA

Answer 9

-1 chromo. = 1 DNA molecule

Question 10

note: nucleus - chromosome - gene - allele - DNA - bases

Question 11

how many bases code 1 amino acid

Answer 11

every 3

Question 12

define inheritance

Answer 12

transmission of genetic information from generation to generation
eg. eye colour, hair colour, height

Question 13

define chromosome

Answer 13

-made of DNA which contains genetic info in the form of genes
eg.
-46 chromo. (23 pairs) in every nucleus - 23 from sperm, 23 from egg
-arranged in pairs

Question 14

define gene

Answer 14

-a length of DNA that codes for a protein
-eg. brown eyed protein

Question 15

define Allele

Answer 15

-an alternative version of a gene
-eg. brown eyed allele

Question 16

define haploid nucleus

Answer 16

-nucleus containing a single set of chromo.
eg. gametes, pollen & ovaries

Question 17

define diploid nucleus

Answer 17

-nucleus containing 2 sets of chromo.
eg. in all body cells (2n = 46 [in pairs])

Question 18

define gametes

Answer 18

sex cells ( sperm & egg)

Question 19

define zygote

Answer 19

-fertilized egg

Question 20

how to make a zygote

Answer 20

-sperm + egg -> zygote
- 23 chromo. [n] + 23 chromo. [n] -> 46 chromo [2n]

Question 21

23rd chromo. of males & females

Answer 21

-male = XY
-female = XX

Question 22

chromo. of egg

Answer 22

X, X

Question 23

chromo. of sprem

Answer 23

X, Y
-50% - X, 50% - Y

Question 24

% of gender out come as girl/ boy

Answer 24

50%

Question 25

define mitosis

Answer 25

-nuclear division giving rise to genetically identical cells (diploid -> diploid)

Question 26

note: mitosis happens after DNA replication

Answer 26

2n - 2n - (mitosis) n

Question 27

where does mitosis happen

Answer 27

-in all body cells except red blood cells & gametes

Question 28

how does mitosis happen

Answer 28

-DNA replicates = 2 copied of 46 chromo. -cell divides -each copy in a daughter cell

Question 29

how many daughter cells in mitosis

Answer 29

2

Question 30

roles of mitosis for humans

Answer 30

-growth -repair of damaged tissues -replacement of cells

Question 31

roles for mitosis for humans and animals

Answer 31

-growth -repair of damaged tissues -replacement of cells -asexual reproduction

Question 32

how are daughter cells in mitosis to each other & parent cell

Answer 32

genetically identical to each other & parent cell

Question 33

what do you call the cell before it divides

Answer 33

parent cell

Question 34

define meiosis

Answer 34

reduction division in which the chromo. no. is halving from diploid to haploid resulting in genetically diff. cells (need for sexual reproduction) (haploid-> diploid -> haploid)

Question 35

where does meiosis happen

Answer 35

-ovaries & testicles

Question 36

how does meiosis happen

Answer 36

-DNA replicates = 2 copies of 23 chromo. -chromo. pairs pair up and sections of DNA is swapped randomly- so genetically diff. -first division = chromo in pairs are separated & cell divides -second division = no DNA replication, chromo. pairs are separated- only chromo. now, cell divides

Question 37

how many daughter cells in meiosis

Answer 37

4

Question 38

roles of meiosis

Answer 38

-reduction division: diploid -> haploid -genetic variation (genetically diff. daughter cells) -making gametes

Question 39

how many division in mitosis & meiosis

Answer 39

-mitosis = 1 -meiosis = 2

Question 40

how are daughter cells in meiosis to each other & parent cell

Answer 40

genetically diff. to each other & parent cell

Question 41

where is chromo. found in cells

Answer 41

nucleus

Question 42

define genotype

Answer 42

genetic make up of an organism in terms of an allele present (always in 2 symbols) eg, BB, Bb, bb

Question 43

define phenotype

Answer 43

observable features of an organism (always in words) eg, brown eyes, blue eyes, curly hair

Question 44

define homozygous

Answer 44

having 2 identical alleles of a particular gene eg, BB, bb

Question 45

define heterozygous

Answer 45

having 2 alleles of a particular gene eg, Bb

Question 46

define pure bred

Answer 46

2 identical homozygous individuals breed tgt eg, BB & BB, bb & bb

Question 47

define not pure bred

Answer 47

2 heterozygous individuals will not pure breed

Question 48

define dominant allele

Answer 48

allele that is expressed if it is in the genotype (always first letter & capital)

Question 49

define recessive allele

Answer 49

allele only expressed when there is no dominant allele in the gene (always small letter)

Question 50

another name for punnett squares

Answer 50

genetic diagram

Question 51

which genotype is parental cross btw

Answer 51

eg, RR x rr homozygous dominant & recessive

Question 52

phenotype ratios for dominant to recessive in parental cross

Answer 52

1: 0 100% dominant allele in all

Question 53

which genotype is F1 cross btw

Answer 53

eg, Rr x Rr heterozygous dominant

Question 54

phenotype ratios for dominant to recessive in F1 cross

Answer 54

3: 1 75% dominant allele in all

Question 55

which genotype is test cross btw

Answer 55

eg, Rr x rr heterozygous dominant & homozygous recessive

Question 56

phenotype ratios for dominant to recessive in test cross

Answer 56

1: 1 50% dominant allele in all

Question 57

how many alleles do gamete have

Answer 57

1

Question 58

how many alleles do genotype have

Answer 58

2

Question 59

where does mitosis happen in plants, say 1

Answer 59

ovary

Question 60

where does mitosis happen in animals, say 1

Answer 60

testis

Question 61

why is mitosis important for gametes

Answer 61

maintains diploid number on fertilisation