/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 156 The pregnancy phase in humans is... [FREE SOLUTION] | 91影视

91影视

Log out

Learning Materials

Features

Discover

Chapter 3: Problem 156

The pregnancy phase in humans is divided into how many trimesters? (a) 2 (b) 4 (c) 3 (d) 5

Short Answer

Expert verified
The pregnancy phase in humans is divided into 3 trimesters.

Step by step solution

01

Understanding the term 'trimester'

The term 'trimester' comes from the Latin 'Tres' for three and 'mester' which is a period of three months. In the context of human pregnancies, this is typically how a pregnancy period is divided.
02

Applying the understanding

Given the meaning of the term 'trimester', we can draw the conclusion that human pregnancy is usually divided into three-trimester periods. Therefore, the correct answer to the exercise is 3.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91影视!

Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Trimesters
Understanding human pregnancy involves dividing it into stages known as trimesters. The term "trimester" means a period of three months, making it a natural way to divide the nine-month pregnancy. Here is how the pregnancy is broken down:
  • The First Trimester covers weeks 1 through 12. During this period, the fertilized egg implants itself in the uterine lining, and essential organs begin to form.
  • The Second Trimester spans weeks 13 to 26. Often, this is when the pregnancy becomes more noticeable. The fetus grows rapidly, moving from tiny beginnings to a length of about 14 inches by week 26. This period may bring increased energy for the expectant mother.
  • The Third Trimester extends from week 27 to birth. The fetus continues to grow and mature. During this time, crucial developments in the brain and nervous system occur, and the fetus prepares for birth.
Throughout each trimester, both the mother and the fetus undergo significant changes, preparing for labor and delivery.
Pregnancy Duration
The total duration of human pregnancy is approximately nine months, or about 40 weeks, from conception to birth. This period is calculated from the first day of the last menstrual period (LMP) because pinpointing the exact moment of conception can be challenging. Typically, pregnancy is described as lasting 280 days:
  • Conceptual Overview: Early on, medical professionals use specific markers to estimate due dates and monitor growth milestones.
  • Factors Influencing Pregnancy Length: Factors such as genetics, maternal health, and whether the expectant mother is carrying multiples (such as twins or triplets) can influence this duration.
  • Variability: While the 40-week standard is common, some pregnancies may be shorter or longer, counting from 37 to 42 weeks as within the normal range.
Understanding the timing aids expectant mothers and healthcare providers in ensuring well-timed prenatal care, preparing for the changes ahead.
Prenatal Development
Prenatal development involves the process a baby goes through while in the womb, divided into three key stages. Each stage is marked by significant growth and development milestones, shaping the foundation for the newborn's life.
  • Germinal Stage: Covering the first two weeks post-conception, this stage is where the zygote forms and implants itself into the uterine wall. It is a critical foundation for the later development stages.
  • Embryonic Stage: From weeks 3 to 8, this phase is where major organs, like the heart and brain, start forming. This is a critical period where the embryo is highly susceptible to teratogens, substances that could cause developmental malformations.
  • Fetal Stage: Lasting from week 9 until birth, this stage is marked by rapid growth and maturation. During this time, organs mature to ensure functionality post-birth, and developments in the central nervous system are pronounced.
Tracking prenatal development helps in assessing the fetus's progress and prepares parents and practitioners for a healthy delivery and infant life.

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Implantation leads to (a) Formation of trophoblast in blastocyst (b) Formation of inner cell mass in blastocyst (c) Pregnancy (d) All the above

Which of the following undergoes unequal division? (a) Primary oocyte (b) Pollen grain of angiosperm (c) Yeast cell during bud formation (d) All the above

Find the false statement. (a) A pair of seminal vesicles is present in human males. (b) A pair of prostates is present in human males. (c) Glans penis is covered by a loose fold of skin called foreskin. (d) Each fallopian tube is about 10 to \(12 \mathrm{~cm}\) long in a human female.

The embryo with \(2^{3}\) or \(4^{2}\) blastomeres is known as (a) Blastocyst (b) Morula (c) Trophoblast (d) Zygote

Secondary oocyte develops zona pellucida around it in the (a) Primary follicle (b) Secondary follicle (c) Tertairy follicle (d) Graafian follicle
See all solutions

Recommended explanations on Biology Textbooks

Communicable Diseases

Read Explanation

Cells

Read Explanation

Substance Exchange

Read Explanation

Chemistry of Life

Read Explanation

Cellular Energetics

Read Explanation

Cell Communication

Read Explanation
View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.