Meiosis and the Scientific Method

Question 1

Explain the cycle of scientific enterprise.

Answer 1

theory, hypothesis, experimental tests, new facts, “are the facts consistent with the theory?” NO: “can theory be altered to accommodate new facts?” (NO: new theory with facts. YES: altered theory with facts.) YES: theory with more facts, new hypothesis

Question 2

the cycle of scientific enterprise

Answer 2

the model of how we make and test theories

Question 3

theories

Answer 3

mental models for how the natural world looks

Question 4

hypothesis

Answer 4

specific answer to a specific question, if…then statement, testable

Question 5

fact/data

Answer 5

supported by observable evidence

Question 6

scientific method

Answer 6

a logical method or procedure to follow when doing the experiment

Question 7

controls, control group

Answer 7

not exposed to testing

Question 8

experimental group

Answer 8

one you are experimenting on (changing something)

Question 9

independent variable

Answer 9

the one thing you change between the 2 groups

Question 10

dependent variable

Answer 10

the change/ the thing that will determine the result, what you are measuring

Question 11

the purpose of mitosis

Answer 11

growth, repair, and replacement

Question 12

heredity

Answer 12

the passing of traits from one generation to the next

Question 13

genetics

Answer 13

the study of herdity

Question 14

asexual repro.

Answer 14

a single parent passes on its genes to its offspring

Question 15

sexual repro.

Answer 15

humans do this, 2 parents giving genes to their offspring creating a unique set of genes

Question 16

what do chromosomes contain and what is their purpose?

Answer 16

contain: DNA and genes
purpose: protection and organization while dividing

Question 17

genes

Answer 17

recipe for making proteins, segment of DNA that codes for a particular protein, gives us our individual looks

Question 18

karyotype

Answer 18

a picture of all of your chromosomes in a cell, arranged in pairs from large to small

Question 19

homologous chromosomes

Answer 19

same types of genes for the same traits, 2 sister chromatids

Question 20

sex chromosomes

Answer 20

1 pair of chromosomes, determine gender: x and y = boy; x and x = girl

Question 21

autosomes

Answer 21

the other 22 pairs of chromosomes

Question 22

Who determines the gender of the baby? The male or female?

Answer 22

male: 1/2 sperm = X and 1/2 sperm = Y, depends on which sperm fertilizes the egg

Question 23

haploid/diploid

Answer 23

n = haploid. 2n = diploid. [n = {23 chromosomes}]

Question 24

sex cells

Answer 24

haploid, come from germ cells (what makes the egg and sperm)

Question 25

gametes

Answer 25

the reproductive/sex cells

Question 26

zygote

Answer 26

a fertilized egg, diploid cell, from mom and dad

Question 27

meiosis

Answer 27

division of germ cells to make sex cells

Question 28

alternation of generations

Answer 28

a life cycle that alternates between haploid and diploid cells

Question 29

explain the circle of life

Answer 29

zygote, mitosis, adult, meiosis, fertilization, back to zygote

Question 30

Explain Meiosis

Answer 30

1. Interphase: DNA coils 2. Meiosis 1: - Prophase: chromosomes form and create homologous pairs which form tetrads, synapsis occurs: pairs stick together, swap DNA: homologous chromosomes take a bit of each others' DNA at chiasmata to form recombinant chromosomes, why no 2 humans are the same, nucleic membrane dissolves - Metaphase: pairs move toward metaphase plate - Anaphase: pairs separate into sister chromatids - Telophase/Cytokinesis: cells pinch off, DNA does not uncoil 3. Meiosis 2: - prophase: chromosomes already formed, spindle forms again - metaphase: chromosomes positioned at metaphase plate - anaphase: sister chromatids separate - telophase/cytokinesis: cells pinch off to form 4 haploid cells

Question 31

overview of meiosis

Answer 31

start with 46 chromosomes. meiosis 1: 23 pairs left. meiosis 2: 23 chromosomes left.

Question 32

chiasma

Answer 32

the point at which homologous chromosomes attach exchange DNA

Question 33

recombinant chromosomes

Answer 33

chromosomes with exchanged DNA

Question 34

another name for meiosis 1 and 2

Answer 34

meiosis 1 = reductional phase | meiosis 2 = equational phase

Question 35

three sources of genetic variation

Answer 35

1. crossing over- recombinant chromosomes (prophase 1) 2. independent assortment- how maternal and paternal chromosomes line up/are arranged 3. random fertilization- any sperm and egg could fertilize each other

Question 36

who is Gregor Mendel?

Answer 36

1800's, father of modern genetics, Austrian monk

Question 37

Where are the reproductive organs in plants?

Answer 37

the flower

Question 38

what plant did Mendel use in his experiments?

Answer 38

pea plants

Question 39

How could Mendel control the breeding of the pea plants?

Answer 39

If he didn't want 2 plants to fertilize each other, he could cut off the male gametes (things that made pollen) on the flower. If he did want 2 certain plants to fertilize each other, he would take a brush to collect the pollen from one plant and use it to pollenate another one.

Question 40

true breeding

Answer 40

a white flower + a white flower = a white flower

Question 41

what are the 3 generations in plants?

Answer 41

P generation- parental generation F (1) generation- the first filial generation F (2) generation- the 2nd filial generation (f1 xf1)

Question 42

locus

Answer 42

where genes are located on a chromosome

Question 43

allele

Answer 43

alternate forms of a gene found at the same locus on homologous chromosomes (gene for color)

Question 44

Mendel's 4 Important Findings

Answer 44

1. There are "factors" in living things that are inherited by offspring. 2. These "factors" occur in pairs. Today we know these "factors" are genes. The alternate versions of a gene are called alleles. 3. Dominant factors are always expressed. Recessive ones have no effect. 4. the law of segregation- the 2 factors for a trait separate during gamete formation (anaphase).

Question 45

How do you represent dominant and recessive traits?

Answer 45

``` P- purple T- tall dominant traits = capital letters, recessive = lowercase, keep same letters p- white t- short ```

Question 46

homozygous

Answer 46

2 of same genes in zygote

Question 47

heterozygous

Answer 47

2 different genes in zygote (dominant wins)

Question 48

phenotype

Answer 48

physical appearance

Question 49

genotype

Answer 49

genetic makeup

Question 50

punnet square

Answer 50

developed by Reginald Punnett, a tool to determine the allele composition of offspring from a cross between 2 individuals