chromosomes, genes, and protein

Question 1

chromosome

Answer 1

a length of DNA, found in the nucleus of a cell; it contains genetic information in the form of many different genes
when cell is dividing they get shorter and flatter
humans have 46 chromosomes in each cell ( x2 23)

Question 2

DNA

Answer 2

a molecule that contains genetic information, in the form of genes, that controls the proteins that are made in the cell, found in the chromosomes

Question 3

gene

Answer 3

a length of DNA that codes for one protein
determine: eye colour, nose type, genetic disease etc.
inherited from your parents

Question 4

alleles

Answer 4

alternative forms of a gene
only one pair of alleles is carried in a gamete

Question 5

a gamete contains….. chromosomes

Answer 5

23 chromosomes
when fused together= 46

Question 6

haploid

Answer 6

a cell with a single set of chromosomes
gamete

Question 7

diploid

Answer 7

two sets of chromosomes
46 chromosomes
zygote

Question 8

mitosis

Answer 8

way in which a plant of animal cell divides when an organism is growing or reparing a damaged part of its body.
genetically identical
also used in asexual reproduction
before mitosis happens the parent cell chromosomes must copy bc each new cell must have 46 (in humans) each
each copy remains to the original one ,the 2 identical ones are called chromatids.
division of the nucleus of the cell not of the cell itself.

Question 9

meiosis

Answer 9

human cells are formed by meiosis ( division of cells)
shares out the chromosomes so that each new cell gets just one chromosome out of the homologous pair
the diploid cells produces haploid daughter cells
its a reduction division
produces genetic variation in the gametes and in the offspring

Question 10

reduction division

Answer 10

what happens in meiosis, where the number of chromosomes is halved (reduced)

Question 11

codominance

Answer 11

alleles that are both expressed in the phenotype when they are both present

Question 12

homozygous

Answer 12

having 2 identical alleles of a particular gene

Question 13

heterozygous

Answer 13

having 2 different alleles of a particular gene

Question 14

genotype

Answer 14

genetic makeup of an organism in terms of the alleles present

Question 15

phenotype

Answer 15

the observable features of an organism

Question 16

dominant allele

Answer 16

an allele that is expressed if it is present ( always shown)

Question 17

recessive allele

Answer 17

an allele that is only expressed when there is no dominant allele of the gene present.

Question 18

inheritance

Answer 18

the transmission of genetic information from generation to generation

Question 19

genetic diagram

Answer 19

a standard way of showing all steps in making predictions about the probable genotypes and phenotypes of the offspring from 2 parents

Question 20

monohybrid cross

Answer 20

a cross where we consider the inheritance of only one gene

Question 21

punnett square

Answer 21

the part of a genetic diagram that shows the predicted genotypes and phenotypes that can result from the random fusion of male and female gametes.

Question 22

pedigree diagrams

Answer 22

a way of showing the phenotypes and sometimes genotypes of family members in several generations. one generation is all in one line.
males are squares
females are circles

Question 23

test cross

Answer 23

a cross to try to determine the genotype of an organism showing the characteristic produces by a dominant allele; the unkown organism is crossed with one showing the recessive characteristic.

Question 24

pure-breeding organisms

Answer 24

always homozygous

Question 25

sex chromosome

Answer 25

chromosomes that determine sex

Question 26

X chromosome

Answer 26

the larger of the 2 sex-chromosomes in mammals
woman’s sex chromosome (XX)

Question 27

Y chromosomes

Answer 27

the smaller of the 2 sex-chromosomes in mammals
man’s chromosome (XY)

Question 28

sex-linked gene

Answer 28

genes that are found on a part of one of the sex chromosomes, usually X, and not the other one; they therefore produce characteristics that are more common in one sex than the other.

Question 29

what is a DNA molecule made of

Answer 29

2 long strand of molecules called nucleotides
4 diff. nucleotides- A,G,C,T
the sequence of bases in the DNA molecules determines the sequence in which amino acids are linked together to produce a protein

Question 30

protein synthesis

Answer 30

happens on ribosomes
to carry info to the ribosomes from the nucleus a messenger molecule called messenger RNA or mRNA is used

Question 31

expressed

Answer 31

used to make a protein; a gene is expressed when the protein that it codes fro is synthesised in a cell
each specialised cell expresses on the gene that it needs, in order to carry out its specific function

Question 32

stem cells

Answer 32

unspecialized cells that are able to divide by mitosis to produce different types of specialized cells
at the stage of embryos we cant see the diff between any cells