IGCSE Biology Paper-3: Specimen Questions with Answers 352 - 353 of 358

Passage

The blood of a fetus does not mix with the blood of its mother, but substances are exchanged across the placenta.

Question 352 (2 of 4 Based on Passage)

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Short Answer▾

Table 17.1 shows five substances that cross the placenta, their direction of movement and the reason for the movement.

Complete Table 17.1.

Five Substances That Cross the Placenta, Their Direction of Movement and the Reason for the Movement
substancedirection of movementreason
oxygen
glucose
urea
amino acid
carbon dioxidefrom fetuswaste gas from respiration

Explanation

Five Substances That Cross the Placenta, Their Direction of Movement and the Reason for the Movement
substancedirection of movementreason
oxygentowards fetusFor respiration
glucosetowards fetusFor respiration
ureafrom fetusWaste from metabolic processes
amino acidfrom fetuswaste from metabolic processes
carbon dioxidefrom fetuswaste gas from respiration

Question 353 (3 of 4 Based on Passage)

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Short Answer▾

Mothers may be encouraged to breast-feed their newborn babies. The first milk that a mother secretes is called colostrum and contains antibodies.

Some mothers bottle-feed their newborn babies with formula milk rather than breast-feed.

Describe four advantages of breast-feeding, other than providing antibodies.

Explanation

Advantages of Breastfeeding for the Baby

  • Superior nutrition
  • There is an increased resistance to infections, and therefore fewer incidents of illness and hospitalization
  • Decreased risk of allergies and lactose intolerance
  • Breast milk is sterile
  • Baby experiences less nappy rash and thrush
  • Baby is less likely to develop allergies
  • Baby experiences fewer stomach upsets and constipation
  • Breastfed infants tend to have fewer cavities
  • Breastfeeding promotes the proper development of baby՚s jaw and teeth.
  • Breastfed infants tend to have higher IQs due to good brain development early in life
  • Babies benefit emotionally, because they are held more
  • Breastfeeding promotes mother-baby bonding
  • In the long term, breastfed babies have a decreased risk of malnutrition, obesity and heart disease compared to formula fed babies.

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