sicence for big test

A cell in the stem tip of a corn plant contains 20 chromosomes. After this cell divides, how many chromosomes should each resulting daughter cell contain?

20

Each body cell of a chimpanzee contains 48 chromosomes. How many chromosomes would normally be present in a gamete produced by this chimpanzee?

24

The chromosome number in an egg cell nucleus of a plant is 14. The normal chromosome number in a root epidermal cell of the same plant is

28

CHROMOSOME NUMBER

2n - number of chromosomes in body cells

ZYGOTE

A diploid cell resulting from the fusion of two haploid gametes; a fertilized ovum

TETRAD

A group of four closely associated chromatids of a homologous pair formed by synapsis.

MORULA

A solid ball of cells resulting from division of a fertilized ovum, and from which a blastula is formed.

Placenta:

A temporary organ that joins the mother and fetus, transferring oxygen and nutrients from the mother to the fetus and permitting the release of carbon dioxide and waste products from the fetus.

Blastula

An animal embryo at the early stage of development when it is a hollow ball of cells

GASTRULA

An embryo at the stage following the blastula, when it is a hollow cup-shaped structure having three layers of cells.

MEIOSIS

CREATES CELLS FOR FERTILIZATION IN THE PROCESS OF SEXUAL REPRODUCTION.

Which statement correctly describes mitotic cell division?

Chromosomes are replicated and two identical daughter nuclei are formed.

MITOSIS

Creates daughter cells genetically identical to the parent cell. USED FOR: Reproduction in unicellular organisms. Development, growth and regeneration/repair in multicellular organisms.

ALL ASEXUAL REPRODUCTION USES

Gametes are produced by mitosis (not meiosis) and after fertilization a diploid zygote is created. The single zygote cell never grows or divides my mitosis. It can only divide by meiosis to produce haploid cells once more, which then produce the main adult body.

A signle set of chromeosomes is

Hapliods

Which statement does not correctly describe an adaptation of the human female reproductive system?

It provides for external fertilization of an egg.

Which statement best describes normal oogenesis in a human?

Meiotic cell division produces one egg and three polar bodies.

Which expression correctly represents a reproductive process that usually occurs in humans where 2n is equal to the number of chromosomes in each body cell?

N+N=2N

MEIOSIS CREATES;

SEX CELLS GAMETES SPERM AND EGG CELLS WITH THE HAPLOID NUMBER CELLS WITH THE n NUMBER

FERTILIZATION

The action or process of fertilizing an egg, female animal, or plant, involving the fusion of male and female gametes to form a zygote

ENDOCRINE SYSTEM

The endocrine system is made up of glands that produce and secrete hormones. These hormones regulate the body's growth, metabolism , and sexual development and function. The hormones are released into the bloodstream and may affect one or several organs throughout the body.

CROSSING OVER

The exchange of genes between homologous chromosomes, resulting in a mixture of parental characteristics in offspring.

WHAT IS SYNAPSIS?

The fusion of chromosome pairs at the start of meiosis.

Menstrual Cycle

The monthly cycle of changes in the ovaries and the lining of the uterus (endometrium), starting with the preparation of an egg for fertilization.

DISJUNCTION

The normal separation or moving apart of chromosomes toward opposite poles of the cell during cell division.

GAMETOGENESIS

The process in which cells undergo meiosis to form gametes.

CLEAVAGE

The rapid mitotic cell division in the early embryo following fertilization, with little or no cell growth.

Differentiation -

Unspecialized cells now begin to specialize, they become different as they continue to divide.

In humans, which cell is produced most directly by mitotic cell division?

a skin cell

Human egg cells are most similar to human sperm cells in their

chromosome number

The ability of cells to pass on their characteristics to new cells is most directly related to the ability of

chromosomes to replicate

Which term describes the series of rapid cell divisions that occur immediately after zygote formation?

cleavage

A pair of chromesomes

dapliods

After the union of sperm and egg, the single-celled zygote develops into a multicellular organism with specialized cells by the processes of

differentiation

A cell resulting from cleavage is similar to a fertilized cell because both cells are

diploid

The separation of homologous pairs of chromosomes during meiosis is known as

disjunction

The inability of sperm cells to move normally could prevent the production of offspring by interfering with

fertilization

An example of sexual reproduction is

fusion of the nuclei of gametes

what does dipliod mean

is a cell or organism that has paired chromosomes, one from each parent. In humans, cells other than human sex cells, are diploid and have 23 pairs of chromosomes. Human sex cells (egg and sperm cells) contain a single set of chromosomes and are known as haploid.

what does hapliod mean

is the quality of a cell or organism having a single set of chromosomes. Organisms that reproduce asexually are haploid. Sexually reproducing organisms are diploid (having two sets of chromosomes, one from each parent). In humans, only their egg and sperm cells are haploid.

Which pair of events would directly result in a constant number of chromosomes in body cells from one generation to the next in sexually reproducing species?

meiosis and fertilization

Which processes lead to the greatest variety of genetic combinations?

meiosis and fertilization

The permanent cessation of the menstrual cycle is known as

menopause

Asexual reproduction primarily involves the process of

mitosis

A zygote develops into a multicellular organism through

mitosis and specialization

Which process allows a mammal to continue to grow in size?

mitosis of body cells

When an organism reproduces asexually, it usually has

only one parent, and is genetically identical to the parent

Which process results in the production of polar bodies?

oogenesis

The reproductive structure in a female mammal that produces sex cells is the

ovary

In humans, the first structure to receive an egg following ovulation is normally the

oviduct

A temporary suspension of the menstrual cycle normally occurs during

pregnancy

Asexual reproduction of diploid organisms normally results in new organisms that contain cells with

the 2n number of chromosomes

The process of mitotic cell division normally results in the production of

two cells with the same number of chromosomes as the parent cell