[Chapter 39] Reproduction Flashcards Preview

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Flashcards in [Chapter 39] Reproduction Deck (172)
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151

What is Prolactin?

A hormone secreted by the mother's anterior pituitary that triggers milk synthesis.

152

What causes milk production to increase?

A decline in progesterone and estrogens after birth.

153

What does human milk have to benefit the newborn child?

It's nutrient rich, and has antibodies to protect it from some viruses and bacteria.

154

Stages of Human Development: What is the Zygote period?

Single cell resulting from fusion of sperm nucleus and egg nucleus at fertilization.

155

Stages of Human Development: What is the Morula period?

Solid ball of cells produced by cleavages.

156

Stages of Human Development: What is the Blastocyte (blastula) period?

Ball of cells with surface layer, fluid-filled cavity, and inner cell mass.

157

Stages of Human Development: What is the Embryo period?

All developmental stages from two weeks after fertilization until end of eighth week.

158

Stages of Human Development: What is the Fetus period?

All developmental stages from ninth week to birth (about 38 weeks after fertilization).

159

Stages of Human Development: What is the Newborn period?

Individual during the first two weeks after birth.

160

Stages of Human Development: What is the Infant period?

Individual from two weeks to about fifteen months after birth.

161

Stages of Human Development: What is the Child period?

Individual from infancy to about ten or twelve years.

162

Stages of Human Development: What is the Pubescent period?

Individual at puberty; secondary sexual traits develop; girls between 10 and 15 years, boys between 11 and 16 years.

163

Stages of Human Development: What is the Adolescent period?

Individual from puberty until about 3 or 4 years later; physical, mental, emotional maturation.

164

Stages of Human Development: What is the Adult period?

Early adulthood (between 18 and 25 years); bone formation and growth finished. Changes proceed slowly after this.

165

Stages of Human Development: What is the Old Age period?

Aging processes result in expected tissue deterioration.

166

Birth before what week is considered premature?

Week 37.

167

What is the earliest a fetus can be born and live, with modern medicine?

As early as 23 weeks, but it may have disabilities.

168

What is the Programmed Life Span Hypothesis?

Life span is genetically determined.

169

What is telomeres?

On chromosomes, caps that are made of DNA and proteins. When only a nub of telomere remains, cells stop dividing and die.

170

How many times do normal human cells divide?

No more than 50 times.

171

Why can cancer and germ cells divide indefinitely?

Because they make telomerase, an enzyme that lengthens telomeres.

172

What is the Cumulative Assaults Hypothesis?

Aging is the outcome of damage at the molecular level.