patterns of heredity the big idea in sexual reproduction, genes are passed from parents to offspring...

Patterns of Heredity

the BIG idea

In sexual reproduction, genes are passed from parents to offspring in predictable patterns.

Living things inherit traits in patterns.4.14.1

Patterns of heredity can be predicted.4.24.2

Meiosis is a special form of cell division.4.34.3

VOCABULARY

KEY CONCEPT CHAPTER HOME

Living things inherit traits in patterns.

A type of reproduction in which male and female reproductive cells combine to form offspring with genetic material from both cells.

sexual reproduction

gene

sexual reproduction

heredity

dominant

recessive

The basic unit of heredity that consists of a segment of DNA on a chromosome.

gene

The passing of genes from parents to offspring; the genes are expressed in the traits of the offspring.

heredity

VOCABULARY



gene

sexual reproduction

heredity

allele

phenotype

genotype

dominant

recessive

A term that describes the allele that determines the phenotype of an individual organism when two different copies are present in the genotype.

dominant

A term that describes an allele that is not expressed when combined with a dominant form of the gene.

recessive

VOCABULARY


Patterns of heredity can be predicted.4.2

ratio

Punnett squarePunnett squares show possible outcomes of heredity.

Ratios and percentages can be used with Punnett squares to express the probability of particular outcomes.

percentage

probability

B b

B

b

BB Bb

Bb bb

B = black furb = brown fur

VOCABULARY


4.3 Meiosis is a special form of cell division.

egg

gamete

sperm

• At the beginning of meiosis I, the parent cell has two copies of each chromosome pair.• During meiosis I, the homologs of the chromosome pair separate; there are two cells, each with two copies of one homolog from each pair.• During meiosis II, the two copies of each homolog separate; each daughter cell has one homolog.

fertilization

meiosis

Meiosis II

1n

1n

1n

1n

Meiosis I

VOCABULARY


A sperm or egg cell, containing half the usual number of chromosomes of an organism (one chromosome from each pair), which is found only in the reproductive organs of a plant or animal.

gamete

A female reproductive cell (gamete) that forms in the reproductive organs of a female and has just a single copy of the genetic material of the parent.

egg

A male reproductive cell (gamete) that forms in the reproductive organs of a male and has just a single copy of the genetic material of the parent.

sperm

VOCABULARY


Part of the process of sexual reproduction in which a male reproductive cell and a female reproductive cell combine to make a new cell that can develop into a new organism.

fertilization

A part of sexual reproduction in which cells divide to form sperm cells in a male and egg cells in a female. Meiosis occurs only in reproductive cells.

meiosis

VOCABULARY


I. Living things inherit traits in patterns.

A. Parents and offspring are similar.

B. Genes are on chromosome pairs.

4.1

KEY CONCEPTSUMMARYKEY CONCEPTSUMMARY


1. One Example

C. Gregor Mendel made some important discoveries about heredity.

2. Mendel’s Conclusions

gene

sexual reproduction

heredity

allele

phenotype

genotype

dominant

recessive

1. Phenotype and Genotype

D. Alleles interact to produce traits.

2. Dominant and Recessive Alleles

CHAPTERRESOURCESCHAPTERRESOURCES

VOCABULARY


II. Patterns of heredity can be predicted.

B. Ratios and percentages can express the probability of outcomes.

4.2


A. Punnett squares show possible outcomes for inheritance.

Patterns of heredity can be predicted.

ratio

Punnett square

percentage

probability


VOCABULARY


III. Meiosis is a special form of cell division.

A. Meiosis is necessary for sexual reproduction.

1. Meiosis I

B. Cells divide twice during meiosis.

4.3


Meiosis is a special form of cell division.

2. Meiosis II

egg

gamete

sperm

fertilization

meiosis

C. Meiosis and mitosis differ in some important ways.


VOCABULARY


X X

X

Y

XX XX

XY XY

VOCABULARY


patterns of heredity the big idea in sexual reproduction, genes are passed from parents to offspring...

Documents